排序方式: 共有61条查询结果,搜索用时 15 毫秒
31.
Fran?ois DelaunayRID=""ID="" To whom correspondence should be addressed Claire Berthier Michel Lenglet Jean-Michel Lameille 《Mikrochimica acta》2000,132(2-4):337-343
The oxidation in air under isothermal conditions of Inconel 718 has been investigated at 900 °C. We have studied the firsts
stages of the high temperature oxidation mechanism. The oxidised samples were examined using a number of surface analytical
techniques including XPS and SEM-EDS. The results have shown that minor alloying elements strongly influence the oxidation
behaviour of the alloy:
Previous studies had shown that the rate of the external oxide scale growth and the intergranular oxide penetration during
oxidation of Inconel 718 at 900 °C in air are lower than those of Inconel X or Incoloy 800. We suggest that the formation
of a quasi continuous scale of the intermetallic phase Ni3Nb at the oxide-alloy interface could have an important contribution to the good oxidation resistance of Inconel 718. 相似文献
32.
Vladimir V. TretyakovRID=""ID="" To whom correspondence should be addressed Sergey V. Kazakov Alexander V. Bobyl Samuil G. Konnikov 《Mikrochimica acta》2000,132(2-4):365-375
An analytical model of an effective atomic number, Z
eff, for simultaneous calculation of composition and thickness of films on substrates that allows for backscattering processes
is presented. Comparison of dependencies of ϕ(ρz) parameters for film elements on electron beam energy, on atomic numbers of a film and a substrate and on film thickness
was done. The errors inherent in EPMA have been determined by comparing experimental data obtained on YBa2Cu3O7−x bulk crystals with model calculations. Possibility of EPMA as an effective technique for investigation of spatially inhomogeneous
objects was demonstrated by studying the correlation between composition and local superconducting properties (values of critical
temperature and critical current) of these films. 相似文献
33.
Independent Directed Triangles in a Directed Graph 总被引:2,自引:0,他引:2
Hong WangRID=""ID="" This research was supported by UIRC SEED GRANTS–KDY 《Graphs and Combinatorics》2000,16(4):453-462
If D is a directed graph of order n≥3 with , then D contains independent directed triangles. Moreover, the condition on the minimum degree is sharp in general.
Revised: April 19, 1999 相似文献
34.
S. GustafsonRID=""ID=""Present address: Courant Institute Mercer St. New York NY USA.¶E-mail: gustaf@cims.nyu.edu I. M. Sigal 《Communications in Mathematical Physics》2000,212(2):257-275
We study the linearized stability of n-vortex (n∈ℤ) solutions of the magnetic Ginzburg–Landau (or Abelian Higgs) equations. We prove that the fundamental vortices (n = ± 1) are stable for all values of the coupling constant, λ, and we prove that the higher-degree vortices (|n|≥ 2) are stable for λ < 1, and unstable for λ > 1. This resolves a long-standing conjecture (see, eg, [JT]).
Received: 16 November 1998 / Accepted: 3 January 2000
RID="*"
ID="*"Research on this paper was supported by NSERC under grant N7901
RID="**"
ID="**"Present address: Courant Institute, 251 Mercer St., New York, NY 10012, USA.¶E-mail: gustaf@cims.nyu.edu 相似文献
35.
K.?S.?Senthil RaaniEmail authorView authors OrcID profile 《Monatshefte für Mathematik》2017,184(3):459-487
Suppose \(\mu \) is an \(\alpha \)-dimensional fractal measure for some \(0<\alpha <n\). Inspired by the results proved by Strichartz (J Funct Anal 89:154–187, 1990), we discuss the \(L^p\)-asymptotics of the Fourier transform of \(fd\mu \) by estimating bounds of for \(f\in L^p(d\mu )\) and \(2<p<2n/\alpha \). In a different direction, we prove a Hardy type inequality, that is, where \(1\le p\le 2\) and \(E_x=E\cap (-\infty ,x_1]\times (-\infty ,x_2]\ldots (-\infty ,x_n]\) for \(x=(x_1,\ldots x_n)\in {\mathbb R}^n\) generalizing the one dimensional results by Hudson and Leckband (J Funct Anal 108:133–160, 1992).
相似文献
$$\begin{aligned} \underset{L\rightarrow \infty }{\liminf }\ \frac{1}{L^k} \int _{|\xi |\le L}\ |\widehat{fd\mu }(\xi )|^pd\xi , \end{aligned}$$
$$\begin{aligned} \int \frac{|f(x)|^p}{(\mu (E_x))^{2-p}}d\mu (x)\le C\ \underset{L\rightarrow \infty }{\liminf }\frac{1}{L^{n-\alpha }} \int _{B_L(0)}|\widehat{fd\mu }(\xi )|^pd\xi \end{aligned}$$
36.
Pagona G Sandanayaka AS Maigné A Fan J Papavassiliou GC Petsalakis ID Steele BR Yudasaka M Iijima S Tagmatarchis N Ito O 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(27):7600-7607
Water-soluble carbon-nanohorn-tetrathiafulvalene (CNH-TTF) nanoensembles were prepared by utilizing positively charged pyrene as an assembly medium and characterized by spectroscopy and electron microscopy. Electronic interactions within the nanoensemble were probed by optical spectroscopy, indicating electron transfer between the TTF units and CNHs after light illumination. 相似文献
37.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. 相似文献
38.
IA Simpson R Bol ID Bull RP Evershed K Petzke SJ Dockrill 《Rapid communications in mass spectrometry : RCM》1999,13(13):1315-1319
Compound specific stable isotope analyses of managed soils using isotope ratio mass spectrometry have been undertaken as a means of determining early land use practices. delta (15)N amino acid signals demonstrate differences between manured grassland, unmanured grassland and continuous cereal cultivation under long-term experimental land use control conditions, with delta (15)N in hydrophobic amino acids providing the most distinctive signals. Analysis of early modern/medieval and of Bronze age anthropogenic soils from Orkney demonstrates that such signals are retained in archaeological contexts. delta (13)C analyses of n- alkanoic acid components of the fossil, Bronze Age, anthropogenic soils suggest a major terrestrial input to these soils, with uniform composition of formation materials. Surficial soils demonstrate the assimilation of isotopically lighter carbon, providing a means of assessing the mobility of the n- alkanoic acids within soils and sediments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
39.
Didier?ArnalEmail authorView authors OrcID profile Olfa?Khlifi 《Algebras and Representation Theory》2018,21(1):219-237
The simple \(GL(n,\mathbb {C})\)-modules are described by using semistandard Young tableaux. Any semistandard skew tableau can be transformed into a well defined semistandard tableau by a combinatorial operation, the Schützenberger jeu de taquin. Associated to the classical Lie groups \(SP(2n,\mathbb {C})\), \(SO(2n+1,\mathbb {C})\), there are other notions of semistandard Young tableaux and jeux de taquin. In this paper, we study these various jeux de taquin, proving that each of them has a simple and explicit formulation as a step-by-step sliding. Any of these jeux de taquin is the restriction of the orthogonal one, associated to \(SO(2n+1,\mathbb {C})\). 相似文献
40.
Kerkines IS Petsalakis ID Argitis P Theodorakopoulos G 《Physical chemistry chemical physics : PCCP》2011,13(48):21273-21281
The absorption and fluorescence spectra of the green emitter DMA-DPH {1-[4-(dimethylamino)phenyl]-6-phenylhexa-1,3,5-triene} and its protonated blue-emitter form have been studied theoretically through time-dependent density functional theory (TD-DFT) and resolution-of-identity 2nd order perturbative coupled cluster (RI-CC2) calculations with basis sets up to augmented triple-ζ quality, in the gas phase and in solvents of different polarity. These systems dispersed in a polymer matrix are of interest for applications in organic light emitting diode devices (OLEDs). Calculations show that the observed absorption and emission spectra correspond to transitions between the S(0) and S(1) states, in both systems. The nature and characteristics of these transitions are discussed. Excellent agreement with experimental data is obtained, both for absorption and emission, provided that the state-specific polarized continuum model (SS-PCM) method is employed for the inclusion of the solvent. 相似文献